Programmed systems most usually check their peripherals and interfaces when the system is started up and/or each time that the peripheral or interface is used. One of the phases of verification includes identifying the peripheral (or interface) and checking its integrity, i.e. ascertaining that it is properly constituted. For this purpose, the program system reads identification numbers of the integrated circuit or circuits providing the interface. The identification number may be provided by the manufacturer's number of the component and/or an identifier of the version of the component. The identification programs contained in the interface drivers read the identification numbers of the integrated circuits and compare them with a list of possible components.
The manufacturers of integrated circuits regularly modify their circuits to make them perform more efficiently. Depending on the integrated circuit, a new version appears every six months to every three years. In general (but not always) a new version of an integrated circuit is compatible with the previous one. Furthermore, the miniaturization of the circuits makes it possible to integrate an ever increasing number of functions into one and the same circuit. Thus, a new circuit may very well replace several older circuits. For example, an interfacing circuit for a serial communications port taking two or three protocols may be replaced by an interfacing circuit that uses several protocols including the required protocols. This enables the manufacturer to make only one circuit instead of about ten of them. Since the new component will automatically be produced in greater numbers than is the case with each of the previous circuits taken individually, the cost of the component will remain unchanged while at the same time enabling the manufacturer to meet the requirements of the market more efficiently, reduce his manufacturing costs and supply a more efficient component.
A problem then arises during the identification of the circuits in a programmed system because the new components may not be identified as corresponding to one of the possible components. Conventionally, the programs are updated to add new identification numbers. Although the updating of the program is not very difficult, its practical implementation raises problems of delays and the unexpected immobilization of equipment following a maintenance operation or a "standard" exchange of certain components.